- Open Access
Postoperative proximal junctional kyphosis correlated with thoracic inlet angle in Lenke 5c adolescent idiopathic scoliosis patients following posterior surgery
BMC Musculoskeletal Disorders volume 23, Article number: 919 (2022)
Proximal junctional kyphosis is a common complication after posterior fusion in patients with adolescent idiopathic scoliosis and is correlated with postoperative changes of thoracic kyphosis. In lenke 5c patients, higher postoperative LL and spontaneous change of TK may produce an effect on final PJK. However, no studies has been performed to evaluate the correlation of PJK with thoracocervical parameters in patients with AIS.
Data from 98 patients who underwent posterior fusion for Lenke 5C AIS with 2 years of follow-up were retrospectively reviewed. Patients in the extended fusion group underwent fusion at levels higher than upper-end vertebra + 2 (n = 38), and those in the thoracolumbar/lumbar (TL/L) fusion group underwent fusion at UEV + 2 or lower (n = 60).
During an average follow-up of 38.1 months, 23 of 98 patients developed PJK. The extended fusion group had a higher incidence of PJK than the TL/L fusion group (14/38 vs. 9/60, respectively; P = 0.01) and a significantly greater decrease in thoracic kyphosis than the TL/L group (P < 0.01). Patients with PJK had a significantly larger preoperative thoracic inlet angle (TIA) than those without PJK (P < 0.01). Multivariate analysis showed that a greater preoperative TIA and extended fusion were associated with PJK. The Scoliosis Research Society 22-item questionnaire score did not significantly differ between the PJK and non-PJK groups.
The preoperative TIA could be a predictor of PJK. Among patients with Lenke 5C AIS, those with a TIA of > 71° are more likely to develop PJK. Additionally, extended fusion in patients with Lenke 5C may increase the risk of PJK.
Proximal junctional kyphosis (PJK) is a common complication after posterior fusion in patients with Lenke 5C adolescent idiopathic scoliosis (AIS) [1,2,3,4]. Multiple studies have shown that the risk factors for PJK are a large lumbar lordosis (LL) angle, large sagittal vertical axis (SVA), and low pelvic incidence (PI) [1,2,3,4]. Other factors strongly associated with PJK in patients with AIS are large preoperative thoracic kyphosis (TK) and large immediately postoperative TK [2, 4, 5]. Previous studies have indicated that the thoracic inlet angle (TIA) is strongly associated with TK and global TK (GTK) in patients with AIS [6,7,8] and that the TIA is a constant morphological parameter that is not changed by the patient’s position or any other conditions. Additionally, these correlations are maintained at 2 years after corrective surgery in patients with Lenke 1 AIS . Hence, the TIA is an ideal parameter that can be used to evaluate the sagittal balance of the proximal thoracic area and may be a predictor of PJK.
The choice of the uppermost instrumented vertebra (UIV) may also be associated with the incidence of PJK in patients with Lenke 5C AIS . Anterior selective thoracolumbar correction and fusion were widely used in the Lenke 5c patients, which might hardly correct the unfused thoracic curve . Meanwhile, posterior thoracolumbar/lumbar (TL/L) fusion is commonly performed to treat Lenke 5C AIS nowadays [10, 11]. To avoid progression of the unfused thoracic curve after TL/L fusion, experienced surgeons may choose to perform extended fusion in patients with Lenke 5C AIS with a bending thoracic Cobb angle of > 20° [12,13,14,15]. Furthermore, Kwan et al.  suggested the performance of extended fusion in patients with a bending thoracic curve of > 15°. However, extended fusion may strongly reduce the TK in the sagittal profile [15, 16]; reduction of TK is a proven risk factor for PJK and may also result in great changes in thoracocervical parameters in patients with AIS [2, 4, 5, 17,18,19,20,21].
The present study focused on analysis of the radiological features of patients with Lenke 5C AIS to identify the correlations among the TIA, PJK, and other sagittal parameters. We also evaluated the relationship between the choice of the UIV and PJK in patients with Lenke 5C AIS.
Materials and methods
The present retrospective study included 98 patients with Lenke 5 AIS from January 2010 to January 2019 who underwent posterior-only surgery in the department of Orthopedic Surgery, West China hospital, Sichuan university. All included patients underwent follow-up for more than 2 years with complete radiographic data. The exclusion criteria were incomplete follow-up data; poor radiographic images; age > 20 years; follow-up period < 2 years; and a history of spine surgery. The present study was approved by the local ethics committee. Patients in the extended fusion group underwent fusion higher than two levels above the upper-end vertebra, whereas patients in the TL/L fusion group underwent fusion below or at the upper-end vertebra + 2. Patients with a Cobb angle of the thoracic curve of > 40° or a bending thoracic curve of > 20° generally underwent extended fusion; however, a few patients with a rigid thoracic curve chose to undergo TL/L fusion to preserve the flexibility of the thoracic spine after acknowledging complete understanding of the benefits and risks of these two procedures. The bending thoracic curve of > 20° and rib hump were prognostic factors of higher final thoracic curves angle . However, no ribs were resected because of the mild rib hump in the lenke 5c patients.
All surgeries were performed by the same surgical team with two senior surgeons. Supraspinous and interspinous ligaments were removed. Smith-Petersen osteotomy was performed before fusion. The Legacy or CD Horizon M8 screw-rod system (Medtronic Sofamor Danek, Inc., Memphis, TN, USA) was used for fixation (5.5 mm titanium rod). Polyaxial screws were inserted in the UIV and LIV. The monoaxial screws were mostly used in the other vertebrae. Rod rotation, apical vertebral derotation (by vertebral column manipulation or direct vertebral rotation), convex compression, and concave distraction were used intraoperatively to correct scoliosis and rotation of the lumbar spine.
Standing full-length posteroanterior and lateral radiographs were routinely taken using a multipurpose digital radiographic fluoroscopy system (SONIALVISION safire 17; Shimadzu Corporation, Kyoto, Japan) preoperatively, at 3 months postoperatively, and at the final follow-up. Radiologic parameters were independently measured and documented on an electronic system by two surgeons who were not involved in the surgeries, and the average values were calculated to increase the accuracy of the measurement of the upper thoracic region .
The coronal parameters measured were the main TL/L Cobb angle, thoracic Cobb angle, reduced bending angle, and correction rate of the two curves. The sagittal parameters measured were the PI, sacral slope (SS), pelvic tilt (PT), LL, PI-LL, TK, GTK, T1 tilt, TIA, proximal junctional angle (PJA), and SVA. TK, GTK, TK, LL, PI, SS, and PT were measured using previously described standard methods (Fig. 1).
The TIA was defined as the angle between the vertical line of the T1 superior endplate and the line passing through the midpoint of T1. The PJA was defined as the Cobb angle between the lower endplates of the UIV and the upper endplates of the two supra-adjacent vertebrae. PJK was defined by the following two criteria with a ≥ 2-year follow-up time: (1) final PJA of ≥ 10° and (2) final PJA at least 10° greater than the preoperative measurement [1, 2, 4, 5]. The presence of both criteria was necessary for considering PJK. An increase in the PJK angle was defined as an increase from the preoperative time to the last follow-up time. Clinical assessments were made using the Scoliosis Research Society 22-item questionnaire (SRS-22).
Student’s t-test was performed to analyze the postoperative changes in the Cobb angle of the thoracic and TL/L curves, PI, PT, SS, SVA, TK, GTK, PI-LL, TIA, and T1 tilt. Bivariate correlation tests, Student’s t-test, the chi-squared test, and receiver operating characteristic (ROC) curve estimations were performed to determine the changes in sagittal balance from the preoperative period to the final follow-up. Data were analyzed using SPSS 21.0 statistical software (IBM Corp., Armonk, NY, USA). To investigate the influence of preoperative measurements on postoperative outcomes, certain preoperative variables (PI, PT, SS, SVA, PJA, PI-LL, GTK, TIA, and T1 tilt) and type of fusion (selective or extended) were selected for inclusion in the multivariate analysis based on the results of the correlation analysis and clinical knowledge. Statistical significance was defined as p < 0.05.
The mean age of the 98 patients with Lenke 5 AIS in this study was 15.6 ± 2.6 years. The patients comprised 77 females and 21 males, and the mean Risser sign was 3.4 ± 1.5. The mean follow-up duration was 38.1 months (range, 24–72 months). The mean Cobb angle of the main TL/L curve was 53.2° ± 9.1° before surgery and 9.4° ± 7.5° at the final follow-up.
Sixty patients underwent selective TL/L fusion, and 38 patients underwent extended fusion. Both groups had an excellent correction rate for the main TL/L curve at the final follow-up (82.6% in the extended fusion group and 82.2% in the TL/L fusion group). The correction rate of the thoracic curve in the extended fusion group (71.9%) was greater than that in the TL/L fusion group (52.6%).
The PI and TIA remained stable after surgery and throughout follow-up in both the extended fusion and TL/L fusion groups. No significant difference in the PI, SS, PT, LL, or SVA were found between the TL/L fusion and extended fusion group preoperatively or at the final follow-up(Table 1). A significant difference was found in the immediate change of TK (− 1.4 ± 11.1 vs. 2.9 ± 6.0, p = 0.01) and in the PJK angle (8.2° ± 7.7° vs. 4.4° ± 4.9°, p = 0.01) between the extended fusion and TL/L fusion groups.
According to our PJK criteria, 23 (23.5%) of 98 patients were considered to have PJK at the final follow-up. We found no significant difference in the PI, PT, SS, LL, PI-LL, or even SVA preoperatively, at 3 months, and at the final follow-up. In addition, the PJA did not differ between the two groups preoperatively. However, the mean preoperative and final TIA,T1 tilt, TK and GTK values in patients with PJK were significantly larger than those in patients without PJK (Table 2). At the final follow-up, a greater proportion of patients in the extended fusion group had PJK than in the TL/L fusion group (14/38 vs. 9/60, p < 0.01). The preoperative TIA of patients with PJK at the last follow-up was larger than that of patients without PJK (73.8° ± 5.0° vs. 64.8° ± 6.8°, p < 0.01), and the ROC curve showed that the cutoff value was 71°.
A correlation analysis between each sagittal parameter and an increasing PJK angle was performed (Fig. 2). Bivariate correlation tests of several radiographic parameters showed that the preoperative TIA (r = 0.61, p < 0.001), preoperative TK (r = 0.44, p < 0.001), final TK (r = 0.52, p < 0.001), final T1 tilt (r = 0.43, p = 0.001), and final GTK (r = 0.46, p < 0.001) had a strong correlation with an increasing PJK angle. Preoperative GTK (r = 0.28, p = 0.006), preoperative T1 tilt (r = 0.27, p = 0.006), final LL (r = 0.30, p = 0.002), and final PI-LL (r = -0.25, p = 0.013) showed a weak correlation with an increasing PJK angle. No marked correlation was found in PI, PT, SS, SVA, or preoperative PI-LL.
The data suggested that the preoperative TIA could be a predictive parameter for the final sagittal balance. We also found that it had a correlation with the final T1 tilt (r = 0.59, p < 0.001), final TK (r = 0.45, p < 0.001), final GTK (r = 0.62, p < 0.001), increasing PJK angle (r = 0.61, p < 0.001), final PI-LL (r = -0.23, p = 0.02), and final LL (r = 0.32, p = 0.002). The final PI, PT, and SS had no significant correlation with the preoperative TIA.
The results of multivariate analysis for preoperative predictors of PJK are presented in Table 3. A greater preoperative TIA (p < 0.001) and extended fusion (p = 0.011) were found to be positive predictors of PJK.
Additionally, patients with PJK showed significantly greater LL and smaller PI-LL at the final follow-up time. No significant difference was found in the preoperative or final SRS-22 scores between postoperative patients with and without PJK (Table 4).
Kim  and Wang  defined PJK in patients with AIS as both a > 10° increase in kyphosis between the UIV and the UIV + 2 and a final PJA of ≥ 10°. These criteria are widely used in patients with AIS [1, 2, 4, 5] and were chosen in our study. Sun et al.  reported that a > 10° increase in PJK occurred after selective fusion in 17.1% of patients with Lenke 5C AIS at 2 years postoperatively, which is comparable with the incidence of PJK found in the present study (23.5%).
Preoperative GTK and TK are alternate parameters that could potentially be used to predict the postoperative change in the sagittal balance of the thoracic spine. However, these parameters are easily influenced by posture because it is difficult to ensure that every patient has a horizontal vision line and is standing perfectly straight during radiography. Therefore, they are not ideal predictors of an increasing PJK angle. In contrast, the TIA is a constant morphological parameter that is not influenced by posture under any conditions, similar to the PI of the spinopelvic unit [6,7,8]. Recent studies have shown significant correlations between the preoperative TIA and GTK angle [6,7,8]. In our study, the TIA could be used to predict the GTK at the final follow-up, which was also strongly correlated with the final increasing PJK angle. Meanwhile, the occurrence of PJK is mainly determined by the variation in the TIA. This may explain the role of the TIA in predicting PJK.
The TIA did not change after surgery or during the 2-year follow-up, it may serve as an appropriate predictor of PJK. According to the ROC curve, a TIA of > 71° was the cutoff point for the occurrence of PJK. A larger preoperative TIA, which predicts larger final GTK, facilitates greater kyphosis of the proximal junction during follow-up (Fig. 3). In the patients who underwent extended fusion of the main thoracic curve, this increase in sagittal kyphosis could only be obtained at the proximal junctional area; thus, the PJA increased (Fig. 4). However, patients with a lower TIA, which indicated lower final GTK and T1 tilt, were much more likely to have final cervical kyphosis .
However, a few patients with a large TIA had relatively small preoperative TK and GTK because of the rotation of the thoracic curve. These patients may have developed an immediate increase in TK after surgery, but the large TIA also meant that they needed a much larger GTK at the final follow-up. In Ogura’s study, the increased TK at final follow-up time was also risk factor of PJK . The increasing TK and GTK immediately after surgery were not enough for these patients; the TK and GTK continued to increase during follow-up, leading to PJK at the final follow-up.
A previous study showed that placement of the UIV cephalad to the upper-end vertebra was associated with an increased risk of PJK Lenke 5C patients . Extended fusion provided more correction in the coronal plane with less restoration of TK [15, 16]. In our study, the extended fusion group had a significantly larger immediate reduction in TK, which is reportedly a risk factor for PJK [2, 4, 5]. In this group, the TK decreased immediately after surgery. However, the GTK needed to stay stable with respect to the preoperative GTK, which facilitated the development of PJK in the proximal thoracic region (Fig. 5). Meanwhile, Clément et al.  showed that long constructs with insufficient TK is more likely to result in PJK. The extended fusion group also had higher risk of PJK in this study. This may partially explain the higher incidence rate of PJK in the present study rather than the one in previous studies after selective TL/L fusion of Lenke 5C patients [3, 4, 23]. Hence, extended fusion should be carefully evaluated in patients with Lenke 5C AIS who have a TIA of > 71°.
Meanwhile, in patients with an immediate increase in TK, the cause of PJK may also be overcorrection of LL . Hence, larger postoperative LL could lead to an immediate increase in TK . Additionally, the spontaneous change to attain sagittal balance may lead to greater PJK to obtain much larger TK to match the overcorrected LL. The importance of maintaining appropriate postoperative SVA was also found in patients with Lenke 5C AIS . AIS patients with preoperative negative SVA may have higher risk of PJK . However, the present study did not find a correlation between PJK and SVA or LL.
No significant difference was found in the clinical outcome between the PJK and non-PJK groups during the ≥ 2-year follow-up. Furthermore, the domain values for pain, self-image, function, mental health, and satisfaction in SRS-22 scores were good or excellent in both groups. This result is similar to that in a recent study . We also believe that a longer follow-up time is needed to evaluate PJK-induced degeneration and back pain.
The present study had several limitations. First, the number of patients was relatively small for a ≥ 2-year follow-up, and there might not have been enough patients with an abnormal preoperative sagittal profile to detect whether this made a difference in the development of postoperative PJK. Second, TL/L fusion may less accurately reflect the TK than might extended fusion because of the unfused thoracic curve. However, the final Cobb angle of the thoracic curve was not significantly different between the two groups. Third, the accuracy of parameter measurements in patients with PJK remains problematic . Although two surgeons measured and documented the patients’ conditions using an electronic system and calculated the average values, it was still difficult to attain high accuracy.
Patients with Lenke 5C AIS who underwent posterior fusion with additional thoracic fusion had a higher incidence of PJK than those who underwent TL/L fusion alone. A TIA of > 71° is associated with a higher risk of PJK. Extended fusion should be performed with greater caution in patients with a TIA of > 71°.
Availability of data and materials
Data will be available upon request to the corresponding author Xi Yang.
Adolescent Idiopathic Scoliosis
Lower End Vertebra
Upper End Vertebra
Lowest Instrumented Vertebra
Central Sacral Vertical Line
C7 Plumb Line
Global Thoracic Kyphosis
Thoracic Inlet Angle
Proximal Junctional Angle
Proximal Junctional Kyphosis
Sagittal Vertical Axis.
Scoliosis Research Society–22 Questionnaire
Kim YJ, Bridwell KH, Lenke LG, et al. Proximal junctional kyphosis in adolescent idiopathic scoliosis following segmental posterior spinal instrumentation and fusion: minimum 5-year follow-up. Spine (Phila Pa 1976). 2005;30(18):2045–50.
Wang J, Zhao Y, Shen B, et al. Risk factor analysis of proximal junctional kyphosis after posterior fusion inpatients with idiopathic scoliosis. Injury. 2010;41(4):415–20.
Sun Z, Qiu G, Zhao Y, et al. Risk factors of proximal junctional angle increase after selective posterior thoracolumbar/lumbar fusion in patients with adolescent idiopathic scoliosis. Eur Spine J. 2015;24(2):290–7.
Lonner BS, Ren Y, Newton PO, et al. Risk factors of proximal junctional kyphosis in adolescent idiopathic scoliosis- the pelvis and other considerations. Spine Deformity. 2017;5(3):181–8.
Kim YJ, Lenke LG, Bridwell KH, Junghoon K, Cho SK, Cheh G, et al. Proximal junctional kyphosis in adolescent idiopathic scoliosis after 3 different types of posterior segmental spinal instrumentation and fusions: incidence and risk factor analysis of 410 cases. Spine. 2007;32:2731–8.
Lee SH, Kim KT, Seo EM, et al. The influence of thoracic inlet alignment on the craniocervical sagittal balance in asymptomatic adults. J Spinal Disord Tech. 2012;25(2):E41–7.
Lee SH, Son ES, Seo EM, et al. Factors determining cervical spine sagittal balance in asymptomatic adults: correlation with spinopelvic balance and thoracic inlet alignment. Spine J. 2015;15(4):705–12.
Zhu C, Yang X, Zhou B, et al. Cervical kyphosis in patients with Lenke type 1 adolescent idiopathic scoliosis: the prediction of thoracic inlet angle. BMC Musculoskelet Disord. 2017;18(1):220.
Huitema GC, Jansen RC, van Ooij A, et al. Predictability of spontaneous thoracic curve correction after anterior thoracolumbar correction and fusion in adolescent idiopathic scoliosis. A retrospective study on a consecutive series of 29 patients with a minimum follow-up of 2 years. Spine J. 2015;15:966–70.
Lenke LG, Betz RR, Harms J, et al. Adolescent idiopathic scoliosis: a new classification to determine extent of spinal arthrodesis. J Bone Joint Surg Am. 2001;83-A(8):1169–81.
Shufflebarger HL, Geck MJ, Clark CE, et al. The posterior approach for lumbar and thoracolumbar adolescent idiopathic scoliosis: posterior shortening and pedicle screws. Spine (Phila Pa 1976). 2004;29:269–76.
Liu Y, Li M, Zhu XD, et al. Retrospective analysis of anterior correction and fusion for adolescent idiopathic thoracolumbar/lumbar scoliosis: the relationship between preserving mobile segments and trunk balance. Int Orthop. 2009;33(1):191–6.
Wang T, Zeng B, Xu J, et al. Radiographic evaluation of selective anterior thoracolumbar or lumbar fusion for adolescent idiopathic scoliosis. Eur Spine J. 2008;17:1012–8.
Sanders AE, Baumann R, Brown H, et al. Selective anterior fusion of thoracolumbar/lumbar curves in adolescents: when can the associated thoracic curve be left unfused? Spine (Phila Pa 1976). 2003;28(7):706–13 discussion 714.
Lark RK, Yaszay B, Bastrom TP, Newton PO. Adding thoracic fusion levels in Lenke 5 curves: risks and benefits. Spine (Phila Pa 1976). 2013;38(2):195–200.
Kwan MK, Chiu CK, Chan TS, et al. Flexibility assessment of the unfused thoracic segments above the “potential upper instrumented vertebrae” using the supine side bending radiographs in Lenke 5 and 6 curves for adolescent idiopathic scoliosis patients. Spine J. 2018;18(1):53–62.
Yanik HS, Ketenci IE, Erdem S. Cervical sagittal alignment in extensive fusions for lenke 3C and 6C scoliosis: the effect of upper instrumented vertebra. Spine (Phila Pa 1976). 2017;42(6):E355–62.
Hwang SW, Samdani AF, Tantorski M, et al. Cervical sagittal plane decompensation after surgery for adolescent idiopathicscoliosis: an effect imparted by postoperative thoracic hypokyphosis. J Neurosurg Spine. 2011;15(5):491–6.
Hiyama A, Sakai D, Watanabe M, et al. Sagittal alignment of the cervical spine in adolescent idiopathicscoliosis: a comparative study of 42 adolescents with idiopathicscoliosis and 24 normal adolescents. Eur Spine J. 2016;25(10):3226–33.
Basques BA, Long WD 3rd, Golinvaux NS, et al. Poor visualization limits diagnosis of proximal junctional kyphosis in adolescent idiopathic scoliosis. Spine J. 2017;17(6):784–9.
Wang F, Zhou XY, Xu XM, et al. Cervical sagittal alignment limited adjustment after selective posterior thoracolumbar/lumbar curve correction in patients with Lenke type 5C adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 2017;42(9):E539–46.
Solla F, Gallo M, Doria C, et al. Prognostic role of rib hump in overlying thoracic curve correction above selective fusion for Lenke 5 idiopathic adolescent scoliosis. Clin Spine Surg. 2018;31(2):E140–5.
Ogura Y, Glassman SD, Sucato D, et al. Incidence of proximal junctional kyphosis with pedicle screws at upper instrumented vertebrae in posterior spinal fusion for adolescent idiopathic scoliosis. Global Spine J. 2021;11(7):1019–24.
Clément JL, Pesenti S, Ilharreborde B, et al. Proximal junctional kyphosis is a rebalancing spinal phenomenon due to insufficient postoperative thoracic kyphosis after adolescent idiopathic scoliosis surgery. Eur Spine J. 2021;30(7):1988–97.
Wang F, Xu XM, Wei XZ, et al. Spontaneous thoracic curve correction after selective posterior fusion of thoracolumbar/lumbar curves in Lenke 5C adolescent idiopathic scoliosis. Medicine (Baltimore). 2015;94:e1155.
My manuscript does not discuss any drugs or devices requiring FDA approval.
Not any funding Source or benefit was received.
Ethics approval and consent to participate
This study was approved by the Ethics Committee of West China Hospital of Sichuan University (IRB number: 2019–852). Informed consent for publication of their anonymized data was obtained from all subjects and/or their legal guardian(s). All methods were performed according to the appropriate guidelines and regulations.
Consent for publication
Any form of individual person’s data was not applicable in this manuscript.
On behalf of all authors, the corresponding author states that there is no conflict of interest.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
About this article
Cite this article
Hu, B., Wang, L., Song, Y. et al. Postoperative proximal junctional kyphosis correlated with thoracic inlet angle in Lenke 5c adolescent idiopathic scoliosis patients following posterior surgery. BMC Musculoskelet Disord 23, 919 (2022). https://doi.org/10.1186/s12891-022-05868-8
- Proximal junctional kyphosis
- Thoracic inlet angle
- Adolescent idiopathic scoliosis
- Sagittal alignment
- Thoracolumbar/lumbar curve